Being silly and joking around might seem simple, but our brains have to work hard to do it. Making a joke means understanding what’s okay to say, being quick, guessing how others will react, and sometimes breaking social rules in a playful way. Until now, most studies on humor focused on humans, and we didn’t know much about how other animals handle it.
A recent study, published in the journal Proceedings of the Royal Society B, gives the first evidence of playful teasing in great apes. Playful teasing is like a warm-up for joking. It’s when one ape does things like poking, hitting, or pulling someone else’s body part, but it’s all in fun, not mean.
Even though scientists like Jane Goodall have talked about apes being silly and teasing each other, this is the first study to really look at it in zoo chimpanzees, gorillas, bonobos, and orangutans.
“Playful teasing is interesting because it’s like someone teasing you as a joke or for fun,” explained primatologist Ammie Kalan from the University of Victoria, Canada, who wasn’t part of the study. “What’s cool about this study is they’re specifically looking at teasing separate from regular play.”
The researchers watched videos of apes interacting in groups to find moments that fit their teasing and play criteria. For example, they looked for instances where one ape started the interaction or checked how the other ape reacted. Each group they studied had at least one young ape, aged 3-5 years, that they kept an eye on in the videos.
Playful teasing comes in many forms
The study found 18 playful teasing behaviors, like poking or hitting, in the videos they watched. They saw 142 of these actions in the 75 hours of footage. Most of the time, young apes started these interactions, doing things like poking or jumping on others until they got their attention, usually from adult apes.
“They would do something, like poke or jump on someone, and then they’d always look at the other ape’s face,” explained lead author Isabelle Laumer from the Max Planck Institute of Animal Behavior, Germany. She thinks this “response-looking” behavior, typical in playful teasing, helps them adjust their actions so the interaction doesn’t turn into a fight or make the adults angry. “I found it surprising and fascinating.”
Unlike playful interactions, which involve back-and-forth play signals like hand raising and head butting, playful teasing starts off one-sided. In over 90% of cases, it’s the teaser who starts it, and only a quarter of the time does it lead to more playful behavior. In almost 25% of cases, the teaser catches their target by surprise from behind.
The young apes mainly tease adult apes, and they choose specific individuals to tease. “They were very intentional about who they teased,” explained Laumer. “It wasn’t random.”
While the study only looked at one group of each ape species, the teasing behavior was similar across all of them. However, because the study included a small number of apes and groups, the researchers advise against assuming this behavior is the same across all species and age groups.
“All the playful teasing they’re describing is centered around a single individual in each group,” Kalan said. “That means you’re already looking at a very different demographic than what you would encounter in a natural grouping setting.” In the wild, she said, a typical ape group would have more than one juvenile, and there might be a lot of playful teasing between juveniles, which helps develop proper socialization behavior.
The findings show how humor might have evolved over time and suggest that the ancestors of apes and humans, who lived 13 million years ago, probably had similar abilities to playfully tease.
This study adds to the many similarities between humans and great apes, such as the ability to laugh, grieve, play, and empathize, which Laumer said could help raise awareness for their conservation. “Great apes are critically endangered, so finding another ability that is shared [with humans] puts the attention on them,” she told Mongabay, “For me, that is a very important aspect of the study.”
